1. Technical Field of the Invention
The present invention relates to a sound field producing apparatus which can set a sound field in accordance with a listener's preference by a simple operation in a stereophonic musical sound reproducing apparatus.
2. Prior Art
It has hitherto been the practice to use a method such as the following to make the sound field comfortable in a car audio system:
(i) a loudspeaker system is constituted as a multi-system by locating a total of four loudspeakers such that two loudspeakers are respectively disposed on the right and left sides at the front end of the car and the remaining two loudspeakers are respectively disposed on the right and left sides at the rear; and
(ii) electrically delayed sound components are mixed with the reproduced sounds, thereby giving an apparent reverberation effect.
According to method (i), the balances of the amount of sound in the right and left directions and in the front and rear directions can be adjusted by attenuators. Differences in listening positions can be allowed for by adjustment of the sound amount balances. Therefore, this method offers the advantage of being able to realize a comfortable sound field in which a listener is surrounded by the sounds at any given listening position. However, with this method, a feeling of expanse and reverberation of sounds cannot be obtained.
According to method (ii), a feeling of reverberation can be obtained and a feeling of expanse of sounds can be achieved in dependence on the listening position of the listener. However, according to this method, since a large amount of electrically delayed signals are also mixed with the sound source whose sound image needs to be formed at a central position, a feeling of localization of sound sources is lost for vocal songs or voice signals from a radio or the like. Accordingly, an unnatural feeling is undoubtedly caused.
In addition, there is a further problem which is common to both methods (i) and (ii), that is, the necessity for the listener to manually operate a number of variable resistors in order to correct the sound field, these operations being quite troublesome.